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New Research Fuels Demand for BPA-Free Food Cans

New Research Fuels Demand for BPA-Free Food Cans

Wednesday, October 20, 2010

Environmental Working Group is a leading advocate in the fight to protect the public from exposures to the synthetic estrogen bisphenol A (BPA), found to leach into canned food from BPA-laced epoxy can linings. On October 20, 2010, EWG wrote federal Food and Drug Administration commissioner Margaret A. Hamburg to alert her and her agency to a pivotal new BPA study that intensifies concerns about the impact of BPA on public health. This letter is the latest in a series of EWG publications and research of many publications on the topic, beginning with a major survey of BPA in canned foods in 2007. (see BPA timeline).

New research reports on the toxicity of bisphenol A (BPA) bear directly on your agency's reassessment of this synthetic estrogen and plastic component.

You know of the ongoing scientific arguments that have delayed actions by your agency to reduce Americans' exposures to this toxic chemical in food packaging, especially in the epoxy resin linings of cans of infant formula and other canned foods. Although literally hundreds of studies demonstrate the toxicity of BPA, including some documenting damage to the reproductive system at everyday levels of exposure, industry scientists seeking to defend clients' interests have persisted in raising questions about the research methods of independent scientists and their relevance to public health.

New research continues to focus on resolving these questions. We assume your team keeps abreast of the latest science on BPA toxicity, but we wanted to bring to your attention one new study in particular. Amidst the growing body of BPA studies, this one on its own overturns several key arguments the agency has used to delay regulation and to justify the public's pervasive, ongoing, daily exposures to this common food pollutant.

We hope the facts uncovered by this new research can catalyze renewed FDA action and lead to measures that will reduce exposures.

The study, conducted by a team led by Gail S. Prins, Ph.D. of the University of Illinois at Chicago and published October 7 in the journal Reproductive Toxicology, demonstrates that in utero exposures to BPA cause precancerous prostate lesions in animals (Prins 2010). The conclusions address several crucial public health issues:

BPA spurred prostate damage at everyday levels of exposure for the public. Often laboratory studies dose animals with toxic chemicals in amounts far greater than what most people experience. The Prins study did not rely on massive amounts of BPA, but instead exposed test animals to the same amounts of BPA that people normally carry in their bodies from everyday exposures – 0.26 to 1.77 ng/mL (nanograms of BPA per milliliter of blood serum) in Prins' rats, versus 0.3 to 4.4 ng/mL (serum or plasma) in people (Vandenberg 2007). Exposures to small amounts of BPA for just three days in early life caused prostate inflammation and lesions in adult rats. Doctors often see these same lesions, called prostate intraepithelial neoplasia (PIN), in adult men. One-third to half of men with high-grade PIN lesions develop prostate cancer (NRDC 2008 citing Kronz 2001 and Park 2001).

The exposure route is relevant. Prins and her team demonstrated that injecting BPA into test animals ("subcutaneous injection") caused the same toxicological impact as oral administration, resolving a long-standing debate in the field of BPA toxicity. These findings negate the prior assumption that ingested BPA was rapidly metabolized and FDA's decision to ignore injection studies demonstrating BPA toxicity at low doses. In particular, it addresses FDA's decision to dismiss as "severely limited" a prior Prins study's relevance for assessing risks to people because it involved "the use of only one dose and subcutaneous injection" (FDA 2008a).

A single dose proves harm. FDA has dismissed this and similar studies that investigate a single BPA dose instead of a spectrum of doses, ranging from high to low. Testing a range of dose levels allows researchers to extrapolate to the potential effects of human exposures that can be thousands of times less potent. But Prins reports that the BPA levels in her experiment overlap directly with those measured in people– averting the need for extrapolation. When a single dose falls within the normal range of human exposures, it can no longer be ignored, even absent documentation of a dose-response trend.

Prostate cancer is the most common cancer in men, a compelling statistic that heightens the need for action on BPA. In 2006, more than 203,000 men developed prostate cancer, and more than 28,000 men died from the disease (CDC 2010). A growing body of research suggests that BPA exposure during development may play a role in the development of prostate cancer in adults. The widespread nature of this disease underscores the urgency of FDA action to reduce BPA exposures from contaminated food and other common sources.

Adding fuel to the fire, in a study published October 8 in the journal Environmental Health Perspectives, a team led by Joe M. Braun of the Harvard School of Public Health has found elevated BPA measurements in pregnant women who eat canned vegetables daily (Braun 2010). This research bolsters a 2007 study by Environmental Working Group that found that BPA had leached into more than half of canned foods tested, and that pregnant women could receive significant amounts of BPA from the canned foods in their diets (EWG 2007).

In January 2010, the agency reversed its long-held position and expressed "some concern" about the safety of everyday exposures. Yet it did not restrict the use of the chemical in food cans and other food packaging, nor did it encourage pregnant women to reduce canned food consumption during pregnancy. Instead, it urged the food processing industry to search for non-BPA alternatives and pledged to continue its own studies of BPA toxicity. It declared that "FDA is not recommending that families change the use of infant formula or foods, as the benefit of a stable source of good nutrition outweighs the potential risk from BPA exposure (FDA 2010)."

We have been surprised and disappointed to see that the agency has not revised its core assumptions of BPA toxicity (FDA 2009 a,b). The ongoing involvement of Mitchell Cheeseman, now the Acting Director of the Office of Food Additive Safety, seems to be a clear impediment to progress. On May 16, 2009 the Milwaukee Journal-Sentinel published FDA emails showing that Cheeseman consulted closely with industry-funded BPA lobbyists while formulating FDA's position on BPA, sought advice from the American Chemistry Council on how to discredit studies of BPA toxicity and oversaw the most recent agency review of the chemical's safety – an assessment that was roundly criticized by FDA's advisory Science Board (Rust and Kissinger 2009, FDA 2008b).

We hope you will show your commitment to protecting the public from BPA by removing Dr. Cheeseman from work related to this hazardous chemical, by revising the agency's 2009 BPA toxicity and exposure assessments (FDA 2009 a,b) to reflect the latest science, and, most importantly, by taking action to reduce the public's exposures to BPA.

FDA (Food and Drug Administration). 2008b. Scientific Peer-Review of the Draft Assessment of Bisphenol A for Use in Food Contact Applications. FDA Science Board Subcommittee on Bisphenol A. October 31, 2008.